Circuit breaker



April 25, 1961 B. A. PITEO, JR, ETAL 2,981,812

CIRCUIT BREAKER Filed July 31, 1958 2 Sheets-Sheet l F9 3 IN VEN TORSBENJAMIN A. PIT-E0 Jm, DAVID B Powzu.

A TTORNEY April 25, 1961 B. A. PITEO, JR., ETAL 2,981,812

CIRCUIT BREAKER Filed July 51, 1958 2 Sheets-Sheet 2 INVENTORS BENJAMINA. Pnzo JR.

DAVID B. powzu. BY WM 1* 7 ATTORNEY United States Patent CIRCUIT BREAKERBenjamin A. Piteo, Jr., Forestville, and David B. Powell, Bristol,Conn., assignors to General Electric Company, a corporation of New YorkFiled July 31, 1958, Ser. No. 752,273

2 Claims. (Cl. 200-114) Our invention relates to electric circuitbreakers and particularly to circuit breakers including auxiliarydevices for the purpose of providing remote indication or control inaccordance with the condition of the circuit breaker mechanism.

There are four types of auxiliary devices commonly used in connectionwith electric circuit breakers. These are:

(1) Auxiliary switches (2) Trip alarms (3) Undervoltage trip devices (4)Remote trip devices Auxiliary switches are switches incorporated withinthe circuit breaker casing which are actuated upon movement of thecircuit breaker mechanism to the open-circuit or otF condition, therebycontrolling a remote device or indicator accordingly.

Trip alarms are special types of auxiliary switches which areincorporated within the circuit breaker casing and are actuated uponmovement of the circuit breaker mechanism to the tripped orautomatically opened position, such as in response to an overload orshort-circuit condition in the circuit controlled by the circuitbreaker.

Undervoltage trip devices are devices incorporated within the circuitbreaker casing which act, when the voltage existing in the circuitcontrolled by the circuit breaker decreases below a predetermined value,to trip or automatically open the circuit breaker, usually for thepurpose of preventing damage to electric motors which would be injuredby running in a condition of low voltage.

Remote trip devices" are devices incorporated within the circuit breakercasing which act in response to the closing of a remotely located switchto cause automatic opening of the circuit breaker mechanism. Theyprovide a convenient means for disconnecting a circuit in an emergency,from a predetermined remote location.

Electric circuit breakers of the type referred to herein include aninsulating casing of molded plastic material, and are provided in twoandthree-pole forms, the insulating casing comprising elongatedsubstantially isolated chambers corresponding in number to the number ofpoles. Thus a two-pole breaker comprises an insulating casing having twoside-by-side elongated chambers and a three-pole breaker comprises aninsulating casing having three side-by-side elongated chambers.

In the construction of such circuit breakers, it is conventionalpractice to provide in each of such chambers at least one relativelystationary contact and one relatively movable contact carried by apivotally supported contact arm, and, in addition, in one of suchchambers, an operating mechanism disposed and arranged to operate all ofsuch contact arms between open and closed circuit positions either (a)manually by means of an operating handle, or (b) automatically by meansof a releasable member normally held by a latch member which in turn isreleasably held by a trip" device actuated in response to abnormalelectrical conditions in the circuit controlled by the circuit breakerto release the latch member.

2,981,812 Patented Apr. 25, 1961 Because of the presence of theoperating mechanism in one pole chamber of the circuit breaker, inaddition to the contacts and contact arm, the room available therein forauxiliary switches or other devices is extremely limited. In accordancewith the prior art, therefore, all such auxiliary devices includingauxiliary switches, trip alarms, undervoltage trip devices, and remotetrip devices have, because of their size and construction, necessarilybeen located only in the pole chambers of such breakers not occupied bythe operating mechanism. The number and combination of such auxiliarydevices which can be used in such breakers according to the prior art istherefore extremely limited. For example, if it is desired to utilize anauxiliary switch and a trip alarm device in a three-pole breaker, bothchambers not occupied by the operating mechanism would have to beutilized. This renders it impossible, therefore, to also provide in thesame breaker, an undervoltage trip device or a remote trip device.Similarly, when any one of the four abovelisted auxiliary devices isincorporated in a two-pole circuit breaker in accordance with the priorart, the one available pole chamber must be utilized and no otherauxiliary device can be provided in the same breaker.

Moreover, auxiliary switch constructions provided by the prior artrequire specially constructed switching assemblies which are relativelylarge and of relatively high cost.

It is an object of the present invention to provide a circuit breakerconstruction incorporating auxiliary devices utilizing standardcommercially available inexpensive switches.

It is another important object of the invention to provide a circuitbreaker construction incorporating auxiliary devices including a tripalarm device which can be mounted in the same pole chamber as thatoccupied by the operating mechanism of the circuit breaker.

It is another object of the invention to provide a circuit breakerconstruction incorporating auxiliary switches wherein a relatively largenumber of such switches may be provided in a single circuit breaker.

It is a further object of the invention to provide a circuit breakerconstruction incorporating auxiliary switches wherein the auxiliaryswitches and operating means therefor may readily be added to or removedfrom the circuit breaker and wherein one or more switches may beutilized and operated by the same operating member.

In accordance with the invention, an electric circuit breaker isprovided including at least two relatively movable contacts and anoperating mechanism therefor including a member movable between twopredetermined positions in accordance with movement of one of saidcontacts between open and closed circuit position. Support means isprovided for mounting a plurality of auxiliary switches each having anoperating member of the push-button type, the operating members beingaligned in side-by-side relation. in a row. A fiat spring member ismounted at one end in the circuit breaker and is arranged to bedeflected by the said movable member upon its movement to apredetermined position. An intermediate portion of the resilient memberengages and operates the operating members of the auxiliary switches,and the resilient member is provided of sufiicient width to engage andoperate the operating members of all the auxiliary switchessimultaneously.

In accordance with the invention in one form, an auxiliary switch issupported in the same pole section as the circuit breaker operatingmechanism and a resilient fiat spring operator is provided whichincludes a part projecting into the path of a releasable or trippingmember of the circuit breaker mechanism so as to be operated upontripping of the circuit breaker.

The aspects hereof considered to be novel will be particularly pointedout in the appended claims. The construction and operation of theinvention in specific embodiments however will be clearly understoodfrom the following detailed description taken in conjunction with theaccompanying drawings in which:

Figure l is a side elevation view of an electric circuit breakerincorporating the invention, a portion of the side wall of theinsulating casing thereof being broken away;

Figure 2 is a fragmentary top plan view showing a portion of the circuitbreaker of Fig. 1;

Figure 3 is a fragmentary side elevation view of a second embodiment ofthe invention, shown in connection with a different circuit breaker;

Figure 4 is an exploded perspective view of the auxiliary switch and itsassociated operator utilized in the form of Figure 3;

Figure 5 is a side elevation view of a third embodiment of theinvention, applied to a circuit breaker similar to that of Figure 3;

Figure 6 is a top plan view of a portion of a circuit breaker as shownin Figures 3 and 5;

Figure 7 is a perspective view of an auxiliary switch assembly includingits associated support and operator as utilized in the form of Figure 5;

Figure 8 is a view of the interior of one of the auxiliary switches.

In the drawings, the invention is shown in Figure l as incorporated inan electric circuit breaker 10 comprising a. generally rectangularinsulating casing having a base portion 11 and a removable cover portion12. For convenience the construction of a single pole chamber of thecircuit breaker 10 is shown and will be described in detail. It will beunderstood however that the circuit breaker 10 includes three polechambers, all substantially identical except that the center polechamber contains the operating mechanism. Each pole section includes apair of relatively stationary contacts 13a and 13b and relativelymovable contacts 140 and 14b. The movable contacts 14a and 14b are bothcarried by contact arm 15 which is pivotally supported at 16 on theinsulated base. The movable contacts 140 and 14b are connected byflexible conductive braids 17 to a terminal strap 18 of removable tripunit 19 which in turn is connected to load terminal 21 by means of strap20. The relatively stationary contacts 13a and 13b are both mounted on aconductive strap 22 which is connected to line terminal 23.

The electric circuit through each pole section may therefore be tracedas follows: from line terminal 23 to conductive strap 22, to stationarycontacts 13a and 13b, to relatively movable contacts 14a and 14b, toflexible conductors 17, to strap 18, to trip unit 19, to strap 20, toload terminal 21.

For the purpose of operating the contact arm 15 and its movable contacts14a and 14b to open and closed circuit position, a suitable operatingmechanism, not shown, is provided, having an operating handle, 24,projecting through an aperture in the top wall of the circuit breakercover 12. The operating mechanism may, for example, be as shown inPatent Number 2,921,169 issued January 12, 1960, to E. B. Judd and I. D.Young, and assigned to the same assignee as the present invention. Thethree movable contact arms 15 of the three-pole sections are gangedtogether for movement as a unit by means of a cross-bar 25 rigidlyattached to each of the arms 15.

For the purpose of providing a plurality of auxiliary switch means whichshall be in one condition when the circuit breaker is in the offposition and in another condition when the circuit breaker is in the onposition, the circuit breaker also includes the following structure.Auxiliary switch supporting means is provided comprising a sheet metalsupport bracket 26 which is attached to the trip unit 19 by suitablemeans such as by bolts 27. The bracket 26 is generally L-shaped and hasa portion in flatwise engagement with the trip unit 19 and a portionextending at right angles thereto.

A plurality of miniature push-button actuated switches 28 are attachedto the bracket 26 by means of bolts 29. Referring particularly to Figure8, each of the switches 28 comprises an insulating casing formed of twomatching insulating halves 30 retained together by means of a rivet 31passing through an aperture 32 in the casing halves. Each of theswitches 28 includes two opposed stationary contacts 33 and 34 mountedon terminal members 35 and 36 respectively, and a movable switch member37 pivotally supported in the casing and electrically connected to theterminal 38. The movable switch member 37 is biased to one side of itspivot by over-center leaf spring 39 and the switch member 37 is adaptedto be operated by a rectilinearly moving push-button operating member40. The construction and arrangement of the switch is such that in theabsence of any actuating force on the operating member 40, the switchmember 37 is biased into engagement with the stationary contact 34 bythe action of the overcenter spring 39. Upon inward movement of theoperating member 40, the contact member 37 suddenly snaps over-centerand is biased into engagement with the stationary contact 33 and is heldthere so long as the operating member 40 is held in the inward-mostposition. Upon release of the operating force on the operating member40, the inherent bias of the spring moves the switch back over-centerinto engagement with the stationary contact 34. The switch 28 alsoincludes aligned apertures 41 in the insulating casing halves throughwhich the mounting bolts 29 extend.

The switches 28 are mounted on the bracket 26 by means of the mountingbolts 29 with two switches on each side thereof. For the purpose ofproviding adequate over-surface or creepage electrical insulationbetween terminals of adjacent switches 28, a sheet insulating barriermember 43 is provided between each adjacent pair of the switches 28. Theswitches 28 are, moreover, mounted on the bracket 26 in the same generalrelation so that the operating members 40 are in side-by-side alignmentin a row. The switches 28 have their terminal members 36, 35 and 38connected by means of conductors 47 to suitable external control devicesextending through an aperture 49 in the side wall of the base 11adjacent its line of meeting with top 12.

For the purpose of actuating the switches 28, a generally L-shapedmember 44 of thin resilient metallic material is provided, attached atone end to the contact arm 15 by means of rivets 45 and having its otherend extending generally at right angles to the contact arm with the freeend portion thereof disposed adjacent but spaced away from the contactoperators 40 of switches 28.

The operation of this embodiment is as follows: when the circuit breakeris in the circuit closed or on" position, as shown in Figure 1, member44 is spaced away from the operators 40 and the switches are thereforeall in the position in which the movable contact is in contact with thestationary contact 36. When the circuit breaker contact arm 15 is movedto the oli or opencircuit position, whether moved manually by means ofthe handle operating member or by means of the circuit breaker tripdevice, the resilient operator 44 is moved into engagement with theplunger members 40 and actuates all switches to the opposite position.The resilient member 44 is accordingly made sufliciently wide to actuateall four of the switches 28 mounted above that particular contact arm.When the contact arm 15 is returned to the circuit closed or onposition, the switches 28 return to the opposite condition as previouslydescribed.

It will be observed that by means of the construction herein provided,it is possible to provide any desired number of switches 28 from one tofour, which can be operated by means of a single operating member 44 ofsimplified construction.

As illustrated in Figure 6, it is therefore possible to mount andoperate as many as eight auxiliary switches in a three-pole breaker,four being mounted in each of the outside pole sections of the breaker.The switches 28 are of standard commercial construction and require nospecial adaptation, and no special ganging operating mechanism isnecessary to operate all such switches at once. Additionally, because ofthe resilient nature of the operator 44, the positioning and adjustmentof the switches 28 is not critical.

In Figures 3 and 4 there is shown a form of the invention adapted toserve as a trip alarm.

This form of the invention is shown as embodied in an electric circuitbreaker 50 having an insulating casing including a base portion 51 and acover portion 52, a movable contact arm 53, and a stationary contact 54.An operating handle 55 is provided for operating the contact member 54between open and closed circuit posi tions, by means of an operatingmechanism shown generally at 56.

The movable contact arm 53 is pivotally supported in the frame 57 on thepivot 58. A pair of toggle links 59 and 60 are interconnected at pivot66 and are pivotally connected at one end 61 to the contact arm 53 andat the other end 62 to a trip member or releasable member 63, which inturn is pivotally supported on the frame 57 at pivot point 64. Thereleasable member 63 is normally restrained in the solid line positionby suitable latch restraining means, 63a, adapted to be operated by atrip device 65. The manually operable handle member 55 is pivotallysupported on the frame 57 at pivot point 67 and has a main operatingtension type spring interconnected between point 68 on the handle memberand toggle knee point 66 of the toggle linkage. Movement of theoperating handle 55 between its extreme positions therefore moves theline of action of the tension spring 69 from one side to the other ofthe pivot point 62 and causes the movable contact arm 53 to move betweenopen and closed circuit position with a snap action as the togglelinkage 59 and 60 is moved between its collapsed and straightenedconditions. Upon release of the releasable member 63 by the tripmechanism 65, the contact member 53 also moves to open circuit position,and the handle member 55 moves to trip-indicating position as indicatedin dotted lines. For the purpose of providing a remote indication of thetripped condition of circuit breaker 50, there is provided an auxiliaryswitch 70 which is rigidly mounted on a supporting bracket 71 by screwsor rivets, not shown, passing through apertures 79 and 80 in the bracketand switch respectively. The supporting bracket 71 is rigidly mounted onthe insulating casing portion of the trip unit by means of screws 84passing through apertures 77. The screws 84 also serve to attach aninsulating barrier 82 and a flat resilient operating member 72 to themember 65 by engagement in apertures 81 and notches 83 in these membersrespectively. The switch 70 is provided with external terminals 76 bywhich it is connected to the remote indicating device. The mountingplate 71 has an elongated intermediate aperture 78 through which theterminals 76 project so that they are readily and conveniently availablefor connection when the cover 52 of the circuit breaker casing isremoved. The resilient member 72 has an outer portion 73 and anintermediate offset portion 74 disposed adjacent to the operating member75 of the miniature auxiliary switch 70.

Upon the release of the releasable member 63, the member 63 engages theend 73 of the resilient operator 72 and deflects the same, causing theintermediate portion 74 to engage the operator 75 to operate the switch70, thereby giving a remote indication of the tripped condition of thecircuit breaker.

It will be observed that this construction provides an extremely compacttrip alarm switch which is mounted in the same pole chamber as thebreaker operating mechanism, thus leaving the two other pole chambers ofa three-pole breaker free to accept other auxiliary switches or otherauxiliary devices such as an undervoltage trip device or a remote tripdevice.

In Figure 5 there is shown another embodiment of the inventioncomprising a circuit breaker 86 similar to the circuit breaker shown inFigure 3, having an insulating casing comprising a base portion 87 and acover portion 88 and a movable contact arm 89 pivotally supported upon apivot 90 and carrying a movable contact member 91 disposed to makecontact with a stationary contact member 92. The movable contact arm 89is disposed and arranged to be moved between closed and open positionsby means of a manually operable handle member 93 through the agency of asuitable operating mechanism, not shown. The circuit breaker 88 includesthree contact arms 89, only one shown, which are rigidly interconnectedfor simultaneous operation by means of a cross-arm 94 of generallyrectangular cross-section, which is rigidly attached to each of thecontact arms 89. In this embodiment of the invention, means is alsoprovided for mounting a number of auxiliary switches 28 by means ofbolts 96 upon a generally L-shaped metallic supporting bracket 97rigidly attached to the insulating casing of a removable trip unit 98 bysuitable means such as by screws 99 in a manner generally similar tothat of the form of Figures 1 and 2.

For the purpose of actuating the switch operators 40 simultaneously inresponse to movement of the contact arms 89, there is provided anangular resilient metallic member 100 which is rigidly attached to theangular bracket 97 by suitable means such as by rivets 101.

The switches 28 are mounted on the bracket 97 by bolts 96, insulatingbarriers 102 being provided between each of the adjacent switches andthe barrier 97.

in operation, so long as the movable contact arm 89 is in the closedcircuit position indicated in Figure 5, the operating member 180 is outof engagement with the plunger type operator 40 and the switches 28 aretherefore in a first condition in which the movable contact member 39 isin engagement with the normally stationary contact 36 or normallyclosed. Upon movement of the contact member 89 to the open-circuitposition, indicated in dotted lines in Figure 5, the cross arm 94rotates about the pivot 90 to the position indicated in dotted lines andmoves member 100 into engagement with the operator members 40 of theswitches 28, moving them to actuated condition.

The form of the support assembly indicated in Figure 7 is generallysimilar to the form of Figures 5 and 6, although only two switches areshown mounted thereon. It will be understood of course, that any desirednumber of switches from one to four may be mounted on the supportingmember 97. The operating member 100 is provided of a Width at leastequal to that required to operate all the operating memberssimultaneously, as indicated in Figure 6. For the purpose of providingthe desired degree of resilience, there is provided an enlarged aperture104 in the member 100 adjacent the bend thereof.

As indicated in Figure 6, a supporting member 105 is provided for use inthe pole section of the circuit breaker opposite from that wherein thesupport 97 is mounted. The support member 105 is shown as generallysimilar to support 97, but substantially the mirror image thereof. Bythe compact and efiicient mounting provided herein, it will be observedthat as shown in Figure 6, it is possible to mount at least eightauxiliary switches in a circuit breaker of the type shown using only thetwo outside pole sections. The auxiliary switch of the form of Figure 3which is operated only upon tripping operation of the circuit breaker,and which is mounted and supported in the central chamber, may, ofcourse, be used in addition to the auxiliary switches shown in Figure 6.There is therefore provided by the present invention, an extremely widelatitude of combinations of auxiliary switches which may be mounted inand operated by the mechanism of a conventional circuit breaker.

It will also be observed that the assembly illustrated in Figmre 7comprising the support member 97 (or its equivalent 105) and theoperating member 100, together with the auxiliary switches mounted onthe bracket, constitutes a subassembly which may be easily manufacturedand sold for addition to existing circuit breakers.

While there has been shown and described only three specific embodimentsof the invention, it will be readily appreciated that many modificationsthereof may be made, and it is therefore intended by the appended claimsto cover all such modifications as fall within the true spirit and scopeof the invention.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. An electric circuit breaker comprising an insulating casing having atleast one operating pole chamber, a relatively stationary contact membermounted in said pole chamber, a movable contact arm pivotally supportedin said pole chamber, a supporting plate of relatively thin sheetmetallic material rigidly mounted on said insulating casing andincluding a portion projecting in edgewise relation over said contactarm in said pole chamber, at least one miniature auxiliary switchmounted on each of the opposite planar surfaces of said projectingportion of said supporting plate in said pole chamber in alignment witheach other transversely of said contact arm, each of said auxiliaryswitches having a plunger type operating member, the operating membersof all of said auxiliary switches being aligned in a row, and anoperating member of thin flat resilient material having one end thereofrigidly mounted on said contact arm and having the other end thereofdisposed adjacent said operating members of said auxiliary switches,said resilient operating member being moved by said movable contact armand engaging said plunger type operating members of all of said auxiliary switches substantially simultaneously when said con tact arm ismoved to disengaged position.

2. An electric circuit breaker as set forth in claim 1 wherein saidresilient operating member has one end rigidly supported on saidauxiliary switch supporting plate and has its other end disposedadjacent said plunger type operating members.

References Cited in the file of this patent UNITED STATES PATENTS2,416,407 Runke Feb. 25, 1947 2,468,645 Steinmayer Apr. 26, 19492,512,386 Sandin et al June 20, 1950 2,656,439 Gelzheiser et al Oct. 20,1953 2,760,028 Walker Aug. 21, 1956

